Glaucoma in the Phakomatoses and Related Conditions

The neural crest is a pluripotential tissue that migrates extensively before differentiating into numerous cell types, including the peripheral nervous system, leptomeninges, melanocytes, Schwann's cells, the skeletal and connective tissue of the face and head. In addition, it contributes to the trabecular meshwork cells and iris stromal melanocytes.1 It appears that SWS, KTW, ODM, PPV, and NF syndromes are all developmental disorders of the neural crest with associated developmental anomalies of the anterior chamber angle accounting for the congenital or developmental glaucoma. Goniotomy or trabeculotomy is the treatment of choice for these patients who develop glaucoma primarily from angle anomalies. In addition to angle maldevelopment, the hamartomas, including vascular malformations (SWS, KTW, PPV), melanocytosis (ODM, PPV), and neurofibroma (NF) also contribute to IOP elevation either by increasing episcleral venous pressure (SWS, KTW, PPV) or infiltrating the trabecular meshwork (ODM, PPV, NF). If the neural crest maldevelopment is less severe, glaucoma can develop later in life secondary to hamartoma complications.